com.saxonica.expr.flwor

## Class GroupByClausePull

- java.lang.Object
- - net.sf.saxon.expr.flwor.TuplePull
  - - com.saxonica.expr.flwor.GroupByClausePull

-     public class GroupByClausePull
      extends TuplePull

  Represents the tuple stream delivered by an "group by" clause. This groups the tuple stream supplied as its input, and outputs a new set of tuples one per group of the input tuples. No groups are output until all the groups have been read.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `GroupByClausePull(TuplePull base, GroupByClause groupBy)`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `close()` Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released
    `boolean` | `nextTuple(XPathContext context)` Move on to the next tuple.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### GroupByClausePull

          public GroupByClausePull(TuplePull base,
                           GroupByClause groupBy)

  - ### Method Detail

    - #### nextTuple

          public boolean nextTuple(XPathContext context)
                            throws XPathException

      Move on to the next tuple. Before returning, this method must set all the variables corresponding to the "returned" tuple in the local stack frame associated with the context object
      Specified by:
        `nextTuple` in class `TuplePull`
      Parameters:
        `context` - the dynamic evaluation context
      Returns:
        true if another tuple has been generated; false if the tuple stream is exhausted. If the method returns false, the values of the local variables corresponding to this tuple stream are undefined.
      Throws:
        `XPathException`

    - #### close

          public void close()

      Close the tuple stream, indicating that although not all tuples have been read, no further tuples are required and resources can be released
      Overrides:
        `close` in class `TuplePull`

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